code: def test_app_tearing_down(app):
      cleanup_stuff = []
  
      @app.teardown_appcontext
      def cleanup(exception):
          cleanup_stuff.append(exception)
  
      with app.app_context():
          pass
  
      assert cleanup_stuff == [None]
  
file_path: flask/tests/test_appctx.py
imports: import pytest
  import flask
  from flask.globals import app_ctx
  from flask.globals import request_ctx
label_desc: Use image node_id 6 for calling a global function with example usage: test_app_tearing_down(app) without return types